Abstract: A request is received at a computer programmed as a database system. The request is a request selected from the group consisting of a query and a utility. A business concept is associated with the request. The business concept is a business concept selected from the group consisting of “who” information defining the source of the request, “what” information defining the processing to be performed by the request, “where” information defining a database object that the request will affect. The computer maps the received request to a database feature setting by mapping the business concept associated with the request to a workload. The workload is defined by a workload definition including a workload classification attribute that maps to the business concept of the request, a workload throttling attribute that defines conditions under which requests assigned to the workload are throttled. Submission of the request to the database system for processing is delayed based on the workload definition.

Abstract: A system, method, and computer-readable medium that facilitate efficient use of cache memory in a massively parallel processing system are provided. A residency time of a data block to be stored in cache memory or a disk drive is estimated. A metric is calculated for the data block as a function of the residency time. The metric may further be calculated as a function of the data block size. One or more data blocks stored in cache memory are evaluated by comparing a respective metric of the one or more data blocks with the metric of the data block to be stored. A determination is then made to either store the data block on the disk drive or flush the one or more data blocks from the cache memory and store the data block in the cache memory. In this manner, the cache memory may be more efficiently utilized by storing smaller data blocks with lesser residency times by flushing larger data blocks with significant residency times from the cache memory.

Abstract: A small table S is outer joined to a large table L on a join condition on a database system with a plurality B of parallel units (PUs). S and L are partitioned across the PUs. Each row in S has a unique row-id. Each row of S is duplicated on all PUs to form Sdup. On each PU, dangling rows in S that do not have a match in L under the join condition are identified and the row-ids of the dangling rows are saved in Tredis. Tredis is partitioned across the PUs. P is formed from dangling rows of S whose corresponding entries in Tredis appear in all PUs. A result is produced by unioning P and I. I is formed by inner joining non-dangling rows of S with L. The result is saved.

Abstract: Techniques for using database metric results are provided. Structure Query Language (SQL) statements are parsed for multiple metric calculations. Each metric calculation is dynamically processed against a database to obtain combined results. The combined results are fed to remaining portions of the SQL statements as a source for or a driver to the remaining portions of the SQL statements.

Abstract: A product demand forecasting methodology is presented that applies daily weight values to a weekly forecast to determine daily forecasts for a product or service. The method determines daily weight values for use in forecasting current product sales by blending daily weight values calculated from historical demand data for both recent weeks and year-prior weeks. Recent weeks are used to account for recent correlations and alternation effects, and year-prior weeks are used to account for seasonality effects. The method automatically calculates a measure of significance for the daily weights calculated from the recent weeks and year-prior weeks. The significance of each week is applied as a weighting factor during the blending of recent weeks and year-prior daily weight values.

Abstract: Apparatus, systems, and methods may operate to receive a request to move at least a portion of a database table stored on a tangible medium from a current partition to a history partition, wherein the database table is partitioned into physical partitions according to a selected mapping update frequency. In response to receiving the request, activities may include modifying a logical partitioning of the database table by updating a mapping of the physical partitions to logical partitions. Other apparatus, systems, and methods are disclosed.

Abstract: A method, computer program, and system are disclosed for executing a utility on a database system having a plurality of database system nodes. Each database system node has an existing load. An increased load on the database system required to execute the utility is determined. The existing load on each of the database system nodes is determined. The increased load is distributed in such a way as to balance the load among the database system nodes.

Abstract: A method, computer program, and computer network are disclosed for transferring data to a database system. The method includes preparing a plurality of input records, each including a plurality of fields and a selector configurable to represent a plurality of states. For each input record of the plurality of input records, the following steps are performed. A state represented by the selector for an input record is read. Based on the state represented by the selector, a subset of the fields for the input record is transferred to the database system.

Abstract: Techniques for processing relational data with a user-defined function (UDF) are provided. Relational input data being requested by the UDF, from within a relational database system, is intercepted and normalized. The UDF is called with the normalized input data and as the UDF produces output data in response to the normalized input data that output data is captured and normalized. In an embodiment, the normalized output data is used to dynamically update a data model within the relational database for the input data.

Abstract: In general, a technique or mechanism is provided to efficiently transfer data of a distributed file system to a parallel database management system using an algorithm that avoids or reduces sending of blocks of files across computer nodes on which the parallel database management system is implemented.

Abstract: An improved workload management system and method for a database system. The improved workload management system evaluates certain workload management rules dynamically at key points during database query execution rather than relying on enforcement prior to query activation. In the case of product join operations, the workload management system evaluates the potential impact on system performance by the product join operation after input tables have been populated, but prior to the execution of the join operation. Delaying workload management enforcement to this point ensures that the sizes of inputs and outputs are reliably known and improves system performance impact estimates at a point early enough to prevent any serious performance degradation from an inefficient product join.

Abstract: Recovering from a failure of a soon-to-fail database system among a plurality of database systems in a multi-database system in processing a request submitted to the multi-database system through a multi-database system session is accomplished. A query band is created for the request. The query band is defined to be an identifier that uniquely identifies the session and the request among the plurality of sessions and plurality of requests being processed by the multi-database system at the time that the request was submitted. The query band is attached to a transaction issued by the multi-database system to the soon-to-fail database system to execute the query. The status concerning execution of the transaction is reported by the soon-to-fail database system. The status includes the query band. The status is logged. The failure of the soon-to-fail database system is detected.

Abstract: A method, computer program, and computer network are disclosed for organizing values of multiple alternative equality conditions between a database column and a set of values. The method includes applying a function to each value to obtain a result for each value. The values are organized into groups where each group includes values with the same result. The values are stored according to the groups. A computer program or database system executes queries that include multiple alternative equality conditions between a database column and a set of values. The database system also includes an optimizer that is configured to apply a function to each value to obtain a result for each value. The values are organized into groups where each group includes values with the same result. The values are stored according to the groups.

Abstract: A database system includes an optimizer to generate resource estimates regarding execution of a request in the database system, and a regulator to monitor progress of execution of the request (and in some examples every step of the request), and to adjust the resource estimates based on the monitored progress. The regulator also adjusts a priority setting of the request according to the adjusted resource estimates.

Abstract: Apparatus, systems, and methods may operate to classify storage locations in a storage medium according to at least three response time grades, to classify data to be stored in the storage locations according to at least three access frequency grades, and to migrate the data between the storage locations according to a predicted access frequency assigned to preemptive allocations of some of the storage locations, based on the response time grade and the access frequency grade associated with the data prior to migration. Other apparatus, systems, and methods are disclosed.

Abstract: A system includes a multi-system database management system having a plurality of database systems. An index selection subsystem combines sets of query information from respective ones of the plurality of database systems into a workload. The index selection subsystem then generates candidate indexes from the workload, and selects recommended indexes from the candidate indexes based on one or more criteria.

Abstract: A system, method, and computer-readable medium that provide mechanisms for tracking the number of queries received for processing for a workload to facilitate arrival rate qualifications to Throughput Service Level Goals are provided. A number of queries counter associated with a particular workload is incremented each time a query assigned to the particular workload is received thereby tracking the arrival rate of workload queries. When a system performance condition comprising a non-compliant system performance level with respect to a Throughput Service Level Goal is identified, the number of queries counter is compared with the Throughput Service Level Goal. If the arrival rate of queries for the workload is greater than the Throughput Service Level Goal of the workload, actions associated with non-compliance of the Throughput Service Level Goal may then be performed.

Abstract: A system, method, and computer-readable medium for dynamic detection and management of data skew in parallel join operations are provided. Rows allocated to processing modules involved in a join operation are redistributed among the processing modules by a hash redistribution of the join attributes. Receipt by a processing module of an excessive number of redistributed rows having a skewed value on the join attribute is detected by a processing module which notifies other processing modules of the skewed value. Processing modules then terminate redistribution of rows having a join attribute value matching the skewed value and either store such rows locally or duplicate the rows. The processing module that has received an excessive number of redistributed rows removes rows having a skewed value of the join attribute from a redistribution spool allocated thereto and duplicates the rows to each of the processing modules.

Abstract: A “group work sorting” technique is used in a parallel computing system that executes multiple items of work across multiple parallel processing units, where each parallel processing unit processes one or more of the work items according to their positions in a prioritized work queue that corresponds to the parallel processing unit. When implementing the technique, one or more of the parallel processing units receives a new work item to be placed into a first work queue that corresponds to the parallel processing unit and receives data that indicates where one or more other parallel processing units would prefer to place the new work item in the prioritized work queues that correspond to the other parallel processing units. The parallel processing unit uses the received data as a guide in placing the new work item into the first work queue.

Abstract: A system, method, and computer-readable medium that facilitate key rotation without disrupting database access are provided. Generation identifiers that specify a particular encryption key are stored in association with cipher text of encrypted columns in database tables. When data is to be read from an encrypted column, the cipher text is read along with the associated generation identifier. An encryption key corresponding to the generation identifier is then read to decrypt the cipher text. When data is to be written to the encrypted column, a most recent encryption key is retrieved from the key repository to encrypt the data. The cipher text is then written to the encrypted column in association with the generation identifier of the key used to encrypt the data. Advantageously, the key rotation may be performed without requiring that the table or database to be taken offline or otherwise unavailable during key rotation.